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Narwhal thermometers in Baffin Bay

Proving that scientists are a resourceful bunch, researchers from the University of Washington and the Greenland Institute of Natural Resources tagged 14 narwhals in Baffin Bay with satellite-linked time-depth-temperature recorders to monitor ocean temperature in a previously little-studied region. The thermometers recorded data over the course of three winters from 2005-2007, and the results of the study were just published in the Journal of Geophysical Research. Not surprisingly, the scientists found that Baffin Bay is warming. Perhaps more interestingly, the narwhals recorded a temperature that was an average 0.9 degrees warmer than the Polar Science Center’s Hydrographic Climatology predicted for the region, allowing scientists a more accurate read of one of the Arctic’s more difficult places to reach.

Narwhals proved more useful than mechanical instruments in remote, hard-to-access Baffin Bay, where the ice cover is thick in winter. Not only do narwhals swim into the frozen body of water, but they also swim deep down in the water column while searching for Greenland halibut. Some dive up to one mile below the surface.

“Their natural behaviour makes them ideal for obtaining ocean temperatures during repetitive deep vertical dives…This mission was a ‘proof-of-concept’ that narwhal-obtained data can be used to make large-scale hydrographic surveys in Baffin Bay and to extend the coverage of a historical database into the poorly sampled winter season.”

The last sentence of the abstract reads,

“This research demonstrates the feasibility of using narwhals as ocean observation platforms in inaccessible Arctic areas where dense sea ice prevents regular oceanographic measurements and where innate site fidelity, affinity for winter pack ice, and multiple daily dives to >1700 m offer a useful opportunity to sample the area”

Site fidelity means that the narwhals’ location is relatively easy to predict, as they often return to the same spots in the summer and winter. They’re even easier to find than man-made buoys, such as the $18,000 one that failed to transmit a signal upon being dropped into the ocean and is now presumed lost.